Process for treating gases



I April 7, 1931 H. J. NIQCHOLS, JR, ET AL PROCESS FOR TREATING 'GASESFiled une; 27, 1 927 m m 0 ll fiomwhumn o N II I 5 i R =3 Q9 &- 4 wUBYNNOMD uavvw I TM m I L u L..Q mx 2 Tm w w m 3R .v k F 1W 3. a mQERRDRW o M: m #11 m A L H M WK WY WNSQWNWR \sO v v W 0 MNSWWNQ Wb USNNNgas from crude or rerun stills is generally- Patented Apr. 7, 1931UNITED STATES HENRY J. NICHOLS, .13., or ROSELLE, AND ERIC w. LUs'rEn,or'wns'rrrsnn, NEW inn PATENT orr es sEY, assrenons 'roSTANDARD'OIIJDEVELOPMENT COMPANY, a CORPORATION or DELAWARE 7Application filed June 27,

The present invention relates to the treatment of gases and morespecifically'comprises a process for extracting gasoline fromhydrocarbon gases Our invention will be fully understood from thefollowing description and the drawingwhich illustrates one form ofapparatusfor carrying out our process.

Thedrawing represents in diagrammatic form an apparatus built accordingto our invention and indicates the flow of gas. through the apparatus. a

In petroleum. refineries where petroleum oil is subjected to differentkinds of treatment, such as ordinary distillation processes and crackingprocesses, large volumes of gas are obtained, and part of this gas-isgenerally used asffuel at the refinery. Gas from,

PROCESS FOR TREATING GASES 1927. Serial No. 201,728.

source may bea pressure still orpreferably one or more batteries ofsuch. stills, (not shown). The expanded gas leaves the cylinder by line9 and is discharged to a. gas

line 13 and. cooler .14 .into the separator 10,

where 'the condensed gasoline is separated and drawn off to tank 15 by aline 16. The

gas in drum 10 is under pressure intermediate between the pressures oftheoriginal gases, preferablyabout 30. lbs. per" sq. in.

ga e and at a temperature below th'at of either of the original ases...

The gasis removed rom the. drum 10'by a line 17 to a recovery-sstemge'nerally indi- I pressure stills or other forms of cracking fi e'dbythe referencec aracb The g e%uipment is generally obtained atpressures a. ove atmospheric, often from. to 100 pounds per square inchor higher, .while the at low'pressure and sometimes even at subthesesources contains more or less gasoline and it is customary to recoverthe gasolineby compression, oil absorption, or adsorption on v activatedcharcoal, as is well known inv the art. In. the present inventiongas atahigh pressure is utilized to compress low pressure still gas in such amanner that gasoline is condensed from either or both gases which 'arethen mined at a common intermediate,

pressure. The last traces of gasoline are preferably removed from thegas before dis-= charge to the boilers or stills as fuel.

Referring to the drawing, the reference character A indicates generallya compressor f of any approved type but which is shown as a single stagepiston compressor of the kind generally in use for compressing air. The

I cylinders 1 and 2 are the steam*and air cylinders respectively andareplaced in alignment, with a single piston rod 3 fitted with pistons 4and 5 in the cylinders 1 and 2. The cylinders are provid with slidevalves 6 and 7 of any preferred type, as will be un'- derstoodi Highpressure gas from any convenient source is fed tocylinder 1' by. pipe8.. Such gasoline is pro need in the expansion, and

in this case it is desirable to by-passthe drum 10 by the line 9,-. a'swill be understood, but

'in' any; case the gasesrfrom the hi h andlOW;

atmospheric pressures. The gas from both of =.P .'BS sources are mixedand ow' by line,

0 either an oil absorption system as is illustrated, or"

18 to the final recovery system B. The final recovery system may beeither of the original gases, is fed to'the bot tom of the'absorptiontower-19. .Theto ver' may beef an preferred type andisshown q fittedwith bu ble cap-plates. The gas flows upwardly through the tower andescapes s the gas. l1ne 20 to be usedfor fuel under sti or boilers. orotherwise as preferred.- Fresh oil is admitted to the topj0f tower.19 bythe line 21 and after absorbing the gasoline from the gas is withdrawnfrom the, tower by line 22. The rich oil is then strip edof gasolinebythe usual methods of thein ustry which need not be described, and isreturned to the absorption tower 19. The gasoline re.-

coveredfrom the rich oil may be in tank 15 or inotherstorage as.desir'ed'.

. As an exampleof-our process,; ,000 cu.

of gas atafpressure of -95 lbs. per sq. in. gage is used to compress30,000 cu. ft. of still gas containin approximately 5 gal,per"1,0Q0" cu;ft. ofgaso ine at; practicallyatmospherlcpressure.. The expanded gasdroppedlin temperatureto 38 Rand the compressed-gas at tains atemperature'of'205- =F.= Theacompressed gas is tliencooled and themixed-gas under pressnrefoi-f 54.3" lbs;v per-Seq; gage.-

assumes a.v temperature of? 50 Approxie mately 100 gals. of gasoline iscondensed";v

In a second example, when; about: e

quantities of the two gases are used, the nal pressure is 35 lbs. persq. -in. gage and-the temperature 39F. A considerable quantity ofgasoline is condensed' fromthe gasand: is suitable for blending purposessimilar to naturalgas gasoline;

While our invention: been described ses" from high pressure: stills, itis applicaer sources, such as natural particularly in; relation topressure and low le to, gas from. at

gas or" coke'oven gas, wherever two gases are available at'high and,lower: pressure sources and. it is desired toobtain a mixture ofthe twoat an intermediatevpressureand a tem-- perature. below either ofl theoriginali gases.

' Our invention is not: to -be limited by any theory ofthe. operationonby any example which may be given-byway-ofiillustration,

but only by the -attached"cl'aims, inwhi'chwe wish to claimallnove1tyinherent in our in vention We cla m: s

1. A process for treating gases. from high andlower: pressure sourcesfor recovery of volatile substances, comprising. compressing the low'pressurejgasbyexp ansion .of the high pressure gas, cooling thecompressed gas,

mixing'said gasesat intermediate: res; sure and removing; volatilesubstances rom n the mixed gases.

. 2. A process for-treating. gases-from high and lower pressure: sourcesfor recovery of, volatile substances, comprising compressing the lowpressure gas by expansion of the high pressure gas, cooling; thecompressed gas, withdrawingthe condensed liquid, mix-- mg said gases atan intermediate pressure drawing, condensed gasoline from" said gas,

withdrawing-condensed. gasoline from the expanded gas and mixing theresidual gases at; a pressure intermediate between those of theoriginalgases.

6; A -process for recovering gasoline from refinery gases, comprisingcompressing low pressure stil-lgas b expansion of high pressure gas:derived rom "cracking apparatus, cooling thecompressed gas, mixing theresulting-gases at pressure above atmospheric;

separating the gasoline condensed by such treatment and; recovering thegasollne remaining ill-the efiluent gas.

7.. A process for treating gases from re1a tively: high and low pressuresources for'rec'overy of volatile substances, comprising compressing thelow pressure gas by, expansion ofthe high pressure gas, cooling the thuscompressed gas whereby a condensate is- 'formed', withdrawing thecondensate, mixingthe gases at a temperature below their initialtemperatures, and absorbing the volatile substances fromthe cooled mixedgases.

8; Aprocess-for treating gases from relatively' high and low pressuresources for recovery' of volatile substancw, comprising I compressingthelow pressure gas by expansion of the-high pressure gas, cooling thethuscompressed gas whereby a condensate is formed1withdrawing thecondensate, mixing" the gases ata temperature below'their initialtemperatures and at a pressure intermediate their initial upressures,and absorbing the (volatile substances from the cooled mixed gases whilemaintaining the intermediate pressure.

' HENRY J. NICHOLS, JR.

, ERIC W. LUSTER;

and volatilem substances from the mixed 3. A process; hydrocarbon: gasesfrom high axidflbwer pressure sources" or o btaining gasoline, comrising com-- pressin the ow pressure-"gas y expansion of the pressure,cooling thefcompressed' gas, mix-v -mg said gases at the intermediatepressure and removingthefgasolinei. condensed from thesame.

iglrpressure' gum an intermediate L A procession hydrocarbon gases"from. high. and lower ressure; sources obtaining" gasoline therefrom,comprismg compressing thelowerpressure gas by expansion-of the highpressure gas, cooling the compressed gas,v withdrawing the, condensedgasoline, mixing gthectcompressed gas Ill

